The preclotting of porous arterial prostheses.

A four-step preclotting method is presented for use with porous filamentous Dacron prostheses in the fully-heparinized patient. The method employs controlled fibrin formation within graft interstices, heparin neutralization of all thrombin remaining in the graft wall, and delay of systemic heparin neutralization until 15--20 minutes after clamp release. The resulting flow surface is impervious, smooth and hypothrombogenic. Experimental data are presented which support the rationale of this four-step preclotting method. Four years of clinical experience with the method are summarized, involving 300 prosthesis limbs used in aortic bifurcation, aortofemoral, femorofemoral, axillary-femoral and femoropopliteal positions in 192 patients. A clinical perspective of preclotting techniques is presented in which the proper use of this new method is suggested.